<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 立即执行函数 不是闭包
        const Box=(function(){
            let name='xx';
            return class {
                get name(){
                    return `名为${name}`
                }
                set name(val){
                    name=val
                }
            }
        })()
        let box=new Box();
        // box.name='yy'
        console.log(box.name);
    </script>
</body>
</html>